The identity of Julius Severianus, author of a short treatise on rhetoric (Praecepta artis rhetoricae) is rather mysterious, given the almost total absence of information concerning him. In addition, although the entire manuscript tradition indicates him as the author of the Praecepta, the Cologne edition attributes the work to Celsus. Today the Severan paternity of the treatise is universally accepted (Woehrer, Halm, Castelli Montanari); in the past some (Leopardi) suggested that it represented a part or a summary of the lost work of Celsus de artibus. The only elements of some importance in the biographical reconstruction are the three passages in which Sidonius Apollinaris (ep. 9, 13, 4; 9, 15, 1; carm. 9, 315) mentions a Severianus, calling him rhetor and contubernalis, and names the dedicatee of the work, Desiderius, who, among other suggestions, has been identified (Caselli Montanari) with a friend of Symmachus. [Alice Borgna; translation L. Battezzato]